Acute Infective Vasitis

36 M with RLQ pain, R inguinal swelling and fever. What is the diagnosis? • Xray of the Week

Figure 1. CT scan of the pelvis on 36 year old male with right lower quadrant pain, right inguinal swelling, and fever.

Figure 2. CT scan of the pelvis demonstrating acute infective vasitis.

A. Axial CT- Inflammation of the right vas deferens (yellow arrows) with mild adjacent edema in the right side of pelvis.

B. Axial CT- Thickening of the right spermatic cord extending into the inguinal canal with mild adjacent edema (red arrows).

C. Coronal CT -Thickening of the right spermatic cord extending into the inguinal canal with mild adjacent edema (red arrows).

Figure 3. Acute infective vasitis. Video going through the axial images on this case.

Figure 4. Ultrasound of acute vasitis shows a heterogenous and thickened vas deferens.

Figure 5. Color Doppler ultrasound of the same section as Figure 4. Note the marked increased blood flow within the spermatic cord.

Discussion:

Vasitis refers to a rare inflammatory disease of the vas deferens (1). There are two forms: acutely painful infectious vasitis and asymptomatic vasitis nodosa (2). The infectious form is typically caused by retrograde spread of organisms such as Neisseria gonorrhoeae, Chlamydia sp., or Escherichia coli from the prostatic urethra or seminal vesicle while vasitis nodosa results from vasectomy (1).

Vasitis often presents as painful swelling in the groin with a palpable mass in the scrotal region (3). It can include urinary tract infection-like symptoms, so it is often misdiagnosed as epididymitis, orchitis, testicular torsion, or prostatitis (4). Due to the inguinal pain and swelling, it is frequently misdiagnosed as an acute inguinal hernia (4). It can also present with leukocytosis, fever, and right lower quadrant pain as seen in this patient (3).

Imaging is important in vasitis as it can prevent unnecessary surgical intervention for other causes of acute groin pain (5-7). The inguinal canal edema can be seen on CT with thickening of the spermatic cord and vas deferens (4) (Figs. 1-3). CT is especially helpful in differentiating between vasitis and acute inguinal hernia. With ultrasound, acute vasitis shows a heterogenous, hypoechoic and thickened vas deferens with hyperemia on color Doppler (3-6)(Figs. 4, 5). Ultrasound can help exclude orchitis, epididymitis, and testicular torsion by color Doppler but it is still difficult to differentiate acute inguinal hernia from vasitis so CT or MRI is recommended (3-5). On MRI, fluid-sensitive sequences show edema of the inguinal canal and spermatic cord (3,7). With appropriate treatment including antibiotics and anti-inflammatory drugs, prognosis is excellent (3).

References:

1. Yang DM, Kim HC, Lee HL, Lim JW, Kim GY. Sonographic findings of acute vasitis. Journal of Ultrasound in Medicine. 2010;29(12):1711-1715. doi:https://doi.org/10.7863/jum.2010.29.12.1711

2. Lin C, Huang TY. Vasitis: a clinical confusion diagnosis with inguinal hernia. Int Braz J Urol. 2019;45(3):637-638. doi:10.1590/S1677-5538.IBJU.2018.0457

3. Chen C-W, Lee C-H, Huang T-Y, Wang Y-M. Vasitis: a rare diagnosis mimicking inguinal hernia: a case report. BMC Urology. 2019;19(1):27. doi:10.1186/s12894-019-0460-xoi:10.1590/S1677-5538.IBJU.2018.0457

4. Eddy K, Piercy GB, Eddy R. Vasitis: clinical and ultrasound confusion with inguinal hernia clarified by computed tomography. Can Urol Assoc J. 2011;5(4):E74-E76. doi:10.5489/cuaj.10116

5. Eddy K, Connell D, Goodacre B, Eddy R. Imaging findings prevent unnecessary surgery in vasitis: An under-reported condition mimicking inguinal hernia. Clinical Radiology. 2011;66(5):475-477. doi:10.1016/j.crad.2010.12.006

6. Yang DM, Kim HC, Lee HL, Lim JW, Kim GY. Sonographic findings of acute vasitis. J Ultrasound Med. 2010;29(12):1711-1715. doi:10.7863/jum.2010.29.12.1711

7. Patel K, Lamb B, Pathak S, Peters J. Vasitis: the need for imaging and clinical acumen. BMJ Case Rep. 2014;2014:bcr2014206994. Published 2014 Oct 17. doi:10.1136/bcr-2014-206994

Updated 08/25/2023: Amara Ahmed is a Radiology Resident at The University of Florida. She did her medical school at the Florida State University College of Medicine. She serves on the executive board of the American Medical Women’s Association and Humanities and Medicine. She is also an editor of HEAL: Humanism Evolving through Arts and Literature, a creative arts journal at the medical school. Prior to attending medical school, she graduated summa cum laude from the Honors Medical Scholars program at Florida State University where she completed her undergraduate studies in exercise physiology, biology, and chemistry. In her free time, she enjoys reading, writing, and spending time with family and friends.

Follow Amara Ahmed on Twitter @Amara_S98

Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice is a radiologist with Cape Radiology Group. Formerly the Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator by AuntMinnie.com.

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